Improvement in manufacturing car-wheels of cast-iron



NITED STATES PATENT ()FFICEO GEO. S. BOSVVORTH, OF TROY, NEW YORK, ASSIGNOR TO ANSON ATWOOD, OF SAME PLACE.

IMPROVEMENT IN MANUFACTURING CAR-WHEELS 0F CAST-IRON.

Specification forming part of Letters Patent No. 2|,S63, dated October 19, 1858.

To all whom it may-concern:

Be it known that I, GEORGE S. BOSWORTH, of the city of Troy, in the county of Rensselaer and State of New York, have discovered certain new and useful Improvements in Manufacturing Cast-Iron Wheels for Railroad-Oars, Carriages, &c.; and I do hereby declare the following to be a full, clear, and exact description thereof, in which my improvements are set forth and ascertained as follows:

My improvements are for the purpose of more perfectly chilling or hardening the wheel (making at the same time a more complete casting without the flaws of cold sheets, waves, or other defects, making also a smooth, even surface and perfect form, undistorted by unequal shrinkage) than has been done by the methods heretofore adopted.

My process is as follows: The wh el may be of any desirable pattern and size, and the molds may be made in the well known ways now practiced, or by anew method devised by me, for which I am about to ask for Letters Patent. The chill or iron ring that surrounds and forms the periphery of the wheel, and which chills or hardens the tread thereof, has before my invention or discovery been used cold or only very slightly warmed, and the general impression has been that it was essential to have the chill, as it is technically named, cool in order to properly chill and harden the portion of the wheel that comes in contact with it. I have discovered that this is not only not essential, but that the effect of hardening known as chilling is much more perfectly accomplished in chills that are highly heated, the effect being deeper and the crystallization more compact, without the defect of flaws, cold sheets, and disintegration, which often accompanies casting in cold chills, (again, by using heated chills, being thus in a more expanded state, when the melted iron flows against them the casting will cool and shrink more slowly, keeping it longerin contact with the chill; it will also contract more equally and chill more deeply and evenly, leaving the tread smoother and the wheel more perfectly round,) than by the ordinary method of casting, giving to the wheel by the perfection of its figure and surface a lighter draft on the road and less wear on the rails in passing over them.

The chill in my process of manufacture, when the melted iron is poured into themold, should be at a high black heat,so that a drop of water will be thrown off from the surface when dropped upon it, but not hot enough to weld the surface of the melted iron to it, and the pouring can be effected while the iron retains a higher degree of heat, and consequently when it is in a state of more perfect liquefaction, thus materially aiding in obtaining a sounder casting and a more perfect wheel than can be attained in the usual mode adopted by the best manufacturers.

Having thus fully described my mode of chilling cast-iron wheels in their manufacture, what I claim, then, as new is- The employment of highly-heated chills, when combined with said molds, in the manner and for the purposes set forth.

GEORGE S. BOSWORTH.

Witnesses:

CHARLES W. ROOTS, WILLIAM HENRY. 

